Photothermal conversion of Ti₂O₃ film for tuning terahertz waves

Dynamic tuning of terahertz (THz) wave is vital for the development of next generation THz devices. Utilization of solar energy for tuning THz waves is a promising, eco-friendly, and sustainable way to expand THz application scenarios. Ti₂O₃ with an ultranarrow bandgap of 0.1eV exhibits intriguing thermal-induced metal-insulator transition (MIT), and possesses excellent photothermal conversion efficiency. Herein, Ti₂O₃ film was fabricated by a two-step magnetron sputtering method, and exhibited an excellent photothermal conversion efficiency of 90.45% and demonstrated temperature-dependent THz transmission characteristics with a wideband at 0.1-1 THz. We supposed to combine photothermal conversion characteristics with temperature-dependent THz transmission properties of Ti₂O₃ film, which could introduce solar light as the energy source for tuning THz waves. Our work will provide new sight for investigating MIT characteristics of Ti₂O₃ at THz regime and exhibit huge potential in the application of tuning terahertz waves in outdoor scenarios in the future.